J-2X test series proves part integrity

May 16, 2011 By Jennifer Stanfield
Engineers, from left, Lakiesha V. Hawkins, David C. Reynolds, and Cynthia L. Sprader inspect the J-2X fuel turbopump first stage nozzle after a successful test series in Marshall's Test Stand 116. Credit: NASA/MSFC/D. Olive

Engineers at NASA's Marshall Space Flight Center gave a key component of the J-2X engine a brisk workout to ensure it can withstand its extreme operating environment. The engine's fuel turbopump first stage nozzle passed the test, performing even better than expected.

The J-2X is a highly efficient and versatile upper stage that can stop and restart in space to support a variety of mission requirements. Full-scale testing begins later this summer but before then, engineers examined the longevity and durability of the engine's fuel turbopump first stage nozzle. The nozzle directs hot gas flow onto the .

The entire operates at extremes, but the fuel turbopump's first stage nozzle really takes a beating. Drastic thermal changes, being super chilled and then immediately super heated, stresses the metal nozzle causing it to rapidly expand and contract which eventually causes it to crack. During engine operations, this turbine nozzle is exposed to cryogenic hydrogen at -422 degrees Fahrenheit and less than two seconds after the start sequence it is hit with hot gases at 1000 degrees Fahrenheit.

Apollo-era rocket scientists studied this same issue on the original J-2 engine. After a battery of tests, Apollo engineers discovered the fuel turbopump first stage nozzle cracked after dozens of starts and stops. While the part cracked, additional tests proved the engine performance and safety were not compromised.

Modeling and simulation for the J-2X suggested the same issue would emerge, so designers selected a new type of nickel metal alloy for the turbopump nozzle which is less brittle and was predicted to hold up better under extreme .

"We did a lot of design and analysis work on this issue to show required part life before we finalized design," said Gary Genge, J-2X turbomachinery manager at NASA's Marshall Center in Huntsville, Ala. "We looked at making dramatic design alterations but changing the geometry of the part would have had a downstream effect we wanted to avoid. Also, the historic data hinted that wiith the improved material and minor changes, the new design might be acceptable."

In total, 43 tests were conducted which simulated the actual engine start and shutdown environment. Non-destructive evaluations were performed at the beginning of every test day and no detrimental condition was ever found.

"By taxing the same part over and over and carefully inspecting frequently, we know with confidence the part is very durable," said Genge. "This knowledge will save time and money in the long run because we can't inspect this area on the actual J-2X engines without disassembling the engine. This thorough test series shows we should be safe throughout the planned test series and we now have a better understanding of its longevity and structural integrity."

Assembly of J-2X Engine 10001, the first engine off the production line, is in full swing at NASA's Stennis Space Center. Full-scale engine testing will begin in June.

The J-2X is designed and built by Pratt & Whitney Rocketdyne of Canoga Park, Calif., for NASA's in Huntsville, Ala.

Explore further: NASA: Engineer vital to 1969 moon landing dies

add to favorites email to friend print save as pdf

Related Stories

Image: Witch's brew aids J-2X engine hardware assembly

Nov 01, 2010

Manufacturing of NASA's J-2X rocket engine includes a Halloween plunge into an icy cauldron of liquid nitrogen. Key components of the J-2X fuel turbopump were assembled at Pratt & Whitney Rocketdyne’s ...

J-2X turbomachinery complete

Dec 23, 2010

(PhysOrg.com) -- NASA and Pratt & Whitney Rocketdyne have successfully completed the heart of the J-2X upper stage rocket engine -- the turbomachinery assemblies -- for the first development engine off the ...

NASA Engineers Complete Engine Test Series For Ares I Rocket

Aug 19, 2008

(PhysOrg.com) -- Engineers at NASA's Marshall Space Flight Center in Huntsville, Ala., have completed a series of tests on a key component of the J-2X engine. The J-2X powers the upper stage of the Ares I rocket, which will ...

NASA to begin developing Ares rockets

Dec 17, 2007

The U.S. space agency said it will begin testing core rocket engine components from the Apollo era this month to help build the Ares rocket.

Recommended for you

NASA's space station Robonaut finally getting legs

12 hours ago

Robonaut, the first out-of-this-world humanoid, is finally getting its space legs. For three years, Robonaut has had to manage from the waist up. This new pair of legs means the experimental robot—now stuck ...

Sun emits a mid-level solar flare

Apr 18, 2014

The sun emitted a mid-level solar flare, peaking at 9:03 a.m. EDT on April 18, 2014, and NASA's Solar Dynamics Observatory captured images of the event. Solar flares are powerful bursts of radiation. Harmful ...

Impact glass stores biodata for millions of years

Apr 18, 2014

(Phys.org) —Bits of plant life encapsulated in molten glass by asteroid and comet impacts millions of years ago give geologists information about climate and life forms on the ancient Earth. Scientists ...

The importance of plumes

Apr 18, 2014

The Hubble Space Telescope is famous for finding black holes. It can pick out thousands of galaxies in a patch of sky the size of a thumbprint. The most powerful space telescope ever built, the Hubble provided ...

User comments : 0

More news stories

NASA's space station Robonaut finally getting legs

Robonaut, the first out-of-this-world humanoid, is finally getting its space legs. For three years, Robonaut has had to manage from the waist up. This new pair of legs means the experimental robot—now stuck ...

Cosmologists weigh cosmic filaments and voids

(Phys.org) —Cosmologists have established that much of the stuff of the universe is made of dark matter, a mysterious, invisible substance that can't be directly detected but which exerts a gravitational ...

UAE reports 12 new cases of MERS

Health authorities in the United Arab Emirates have announced 12 new cases of infection by the MERS coronavirus, but insisted the patients would be cured within two weeks.